CFI Building Construction & Fire Behavior 2 — Questions and Answers
Question 1: Which building construction type uses exterior walls of noncombustible or limited-combustible materials with a combustible interior?
- Type I (Fire Resistive)
- Type II (Noncombustible)
- Type III (Ordinary) (Correct answer)
- Type V (Wood Frame)
Correct answer: Type III (Ordinary)
Type III (Ordinary) construction uses noncombustible exterior walls but allows combustible interior framing and components.
Question 2: What phenomenon occurs when superheated gases at ceiling level suddenly ignite, causing simultaneous ignition of all combustible surfaces in a room?
- Backdraft
- Flashover (Correct answer)
- Rollover
- Smoke explosion
Correct answer: Flashover
Flashover is the near-simultaneous ignition of all exposed combustible material in an enclosure, typically occurring when upper layer temperatures reach 500–600°C.
Question 3: A fire inspector notes that a renovated building has steel columns unprotected by fireproofing. Which hazard does this create?
- Reduced fire load
- Accelerated fire spread through the HVAC
- Potential structural collapse due to steel losing strength at elevated temperatures (Correct answer)
- Increased compartmentalization
Correct answer: Potential structural collapse due to steel losing strength at elevated temperatures
Unprotected steel loses approximately 50% of its yield strength at around 1,100°F (593°C), leading to possible structural collapse.
Question 4: In the context of fire behavior, what does 'fuel-controlled fire' mean?
- The fire is controlled by suppression systems
- Combustion rate is limited by available fuel rather than oxygen (Correct answer)
- The fire department has contained the fire
- Fire spread is controlled by sprinklers
Correct answer: Combustion rate is limited by available fuel rather than oxygen
A fuel-controlled fire has adequate oxygen but limited fuel, so the combustion rate is governed by the amount and arrangement of combustible materials.
Question 5: Which feature of Type IV (Heavy Timber) construction helps it perform well in fire?
- Steel connectors resist heat
- Large wood members char on the outside, slowing combustion (Correct answer)
- Gypsum wallboard provides insulation
- Concrete cores absorb heat
Correct answer: Large wood members char on the outside, slowing combustion
Heavy timber members develop a self-insulating char layer that slows the rate of combustion and helps maintain structural integrity longer than lighter wood members.
Question 6: What is the primary reason balloon-frame construction is considered especially dangerous during a fire?
- It uses noncombustible materials that reflect heat
- Wall cavities run continuously from foundation to roof, allowing rapid vertical fire spread (Correct answer)
- It has no attic space to contain smoke
- Steel tie rods conduct heat between floors
Correct answer: Wall cavities run continuously from foundation to roof, allowing rapid vertical fire spread
Balloon-frame construction has continuous wall stud cavities from the sill plate to the roof that act as chimneys, rapidly spreading fire and gases to upper floors and attic spaces.
Question 7: During fire investigation, an inspector finds intense burning at floor level with little ceiling damage. This pattern most likely indicates:
- A fast-moving surface fire
- Low-burning fuel such as flammable liquid pooled on the floor (Correct answer)
- Flashover occurred early
- Ventilation-controlled conditions throughout
Correct answer: Low-burning fuel such as flammable liquid pooled on the floor
Flammable liquid fires burn close to the floor surface, producing characteristic low-burn patterns and pour patterns that differ from typical upward-spreading fires.
CFI Building Construction & Fire Behavior 2
Which building construction type uses exterior walls of noncombustible or limited-combustible materials with a combustible interior?